Powerful Low Frequency RadarJuha Vierinen

MIT Haystack Observatory

+ = LOFRAD

High power aperture radiator

Modern low frequency radio

telescope

Wednesday, May 25, 16

What could you do with “LOFRAD”?

• Establish a radio science playground

• Attempt to revisit Solar radar (Eshelman et.al.,1960; James et.al., 1970)

• Multi-static radar, multi k-space aeronomy (FAI, MST, ISR). Similar to EISCAT 3D, but with additional frequency dimension.

• 3d vector, electric field, current, neutral wind

• Lunar subsurface imaging

• Meteor head echoes (first instrument with truly unambiguous trajectories)

• Magnetospheric radar

Wednesday, May 25, 16

(Parts of science case from EISCAT 3D apply)

What could you do with “LOFRAD”?

Wednesday, May 25, 16

Solar Radar

(Rodriguez 2000)

• Early measurements not really well understood (Stanford, El Campo). Jicamarca experiment with negative result (Coles 2004).

• Modern phased array radio astronomy receivers (LOFAR and LWA)

• Lots of interest in developing idea: Coles, Kassim, Rodriguez, Isham, Thide, Sulzer, Hysell...

Wednesday, May 25, 16

Meteors

Solar Radar

(Close et.al., 2002)

• Low frequency means large RCS

• Multi-static receive allows unambiguous trajectory determination

• The most sensitive radar micrometeor survey capability

(Chau et.al., 2007)

• Accurate distribution of dust

• How much dust enters our atmosphere?

• Are there interstellar meteors?

Wednesday, May 25, 16

Lunar

• A high power VHF radiator with multi-static phased array receiver antennas could potentially do planetary radar

• Lunar subsurface radar observations

• Maybe other planetary targets

(Thompson 1978)

Wednesday, May 25, 16

Kilpisjärvi Atmospheric Imaging Receiver Array

(Vierinen et.al., 2013, McKay-Bukowski et.al., 2015) http://kaira.sgo.fi10 - 250 MHzWednesday, May 25, 16

backup slides

Wednesday, May 25, 16

+ = SKARAD

Powerful High Frequency Radar

Wednesday, May 25, 16

KAIRA

• Plasma parameter estimation from multistatic, multibeam incoherent scatter data (Virtanen et.al., 2014)

• Ionospheric electron density profiles inverted from a spectral riometer (Kero et.al., 2014)

• Broadband meter-wavelength observations of ionospheric scintillation (Fallows et.al., 2014)

• All-sky interferometric riometry (McKay et.al., 2015)

Wednesday, May 25, 16

Existing solar radar hardware possibilities

• Arecibo heater (8 MHz)

• SURA/UTR-2 (750 kW, 8.9 MHz)

• LOFAR, LWA (5-80 MHz)

• Jicamarca (200 kW, 49.9 MHz)

• El Campo (500 kW, 38.25 MHz)

Wednesday, May 25, 16